Composite products comprising reinforcing material surrounded by a matrix of metal combine the stiffness and wear resistance of the reinforcing phase with the ductility and toughness of the metal matrix. In order to produce metal matrix components, the appropriate reinforcement material is first oriented within a mold. Then, the desired liquid metal is forced into the mold so that it completely fills the interstices of the reinforcement material.
There are many instances when it would be desirable to form internal structures within the metal matrix component. An example of this is when the thermal characteristics of the metal matrix composite is of functional importance. By adding channels within a metal matrix component, circulating fluid can be used to cool or heat the component more efficiently than by external means. Alternatively, sealed voids within a metal matrix component can be used to selectively alter the insulative properties or weight of a metal matrix component.
In many cases, the complexity of these structures makes it impossible to produce a mold which can form the desired shape and void characteristics of the metal matrix component and still be released therefrom to remove the component from the mold. Further, the superior strength, abrasive properties of metal matrix materials makes it expensive, if not impossible, to form the voids after the component is solidified.
Internal structures within metal matrix composites can be used for cooling passages, welding surfaces, electrical feedthroughs, drill locations and for mirror surfaces.